• Planck;
  • Boltzmann;
  • statistics;
  • quantum theory.


In the last forty years a vast scholarship has been dedicated to the reconstruction of Planck's theory of black-body radiation and to the historical meaning of quantization. Since the introduction of quanta took place for combinatorial reasons, Planck's understanding of statistics must have played an important role. In the first part of this paper, I sum up the main theses concerning the status of the quantum and compare the arguments supporting them. In the second part, I investigate Planck's usage of statistical methods and the relation to Boltzmann's analogous procedure. I will argue that this way of attacking the problem is able to give us some interesting insights both on the theses stated by the historians and on the general meaning of Planck's theory.